2006-09-14 04:36:36 · 5 answers · asked by vijai k 1 in Science & Mathematics ➔ Physics
If you're standing still and it's the ground that's keeping you from accelerating due to the gravitational force, the simple term is the contact force. The component of that force which is 'normal' (perpendicular) to the surface is the normal force. The component which is parallel to the surface is the friction force. If you are on perfectly level ground, the friction force is zero.
Your movement is the result of the sum of all forces acting upon you. Besides gravity, the only way to apply a significant amount of force to you is by contact with something. This could be the earth, an airplane, a rocket ship, or a fluid. If you are floating in water, you could call the bouyant force from the displaced water a contact force, since the force is applied to you where the water is in contact with you.
Even though it's called a force, it's really just a description of how some force is applied.
2006-09-14 06:15:12 · answer #1 · answered by Frank N 7 · 1⤊ 0⤋
Its called normal force.
For example, that would be the force the ground is exerting up on something like a box that is at rest on the ground.
It is not always equal and opposite to gravity (which is actually an acceleration, not a force.. force of gravity would be mass*gravity), thats only if the object is at rest with no other forces acting upon it. If you have, say for example, you're pushing the box down onto the ground and it's at rest, the normal force would be in the the force of gravity plus the force you're exerting down, and it would be in the upward direction.
2006-09-14 11:44:00 · answer #2 · answered by Nes 3 · 1⤊ 1⤋
The force that keeps you on the ground (under influence from gravity you might expect to fall all the way to the center of the Earth) is called the normal force - it's the force that the ground excites on your feet.
If you're svimming, the force is called buoyancy - it's the net water pressure on your body, which is upwards because water pressure increases with depth, so the pressure from below is stronger than the pressure from above.
2006-09-14 11:47:59 · answer #3 · answered by helene_thygesen 4 · 0⤊ 0⤋
the 'normal' force is not always opposite in direction to gravity either, as it suggests in the name, this force is a 'normal' to any surface an object rests on. so if it's a box/mass on a inclined plane the normal is at right angles to the slope and not in the exact opposite direction of weight. however there will be a vertical component of the normal counter acting the weight
2006-09-14 12:01:20 · answer #4 · answered by pat_arab 3 · 1⤊ 0⤋
would it be "Relative'
2006-09-14 11:40:34 · answer #5 · answered by Iceman 3 · 0⤊ 2⤋